Pharmacokinetic based study on "lagged stimulation" of Curcumae Longae Rhizoma - Piper nigrum couplet in their main active components' metabolism using UPLC-MS-MS

BACKGROUND

Curcumae Longae Rhizoma is one of the commonly used traditional Chinese medicines, which has multiple biological activities such as relieving stagnation and stasis, pain alleviation, curing amenorrhea and wounds. However, its main active component-curcumin has poor absorption and very fast metabolism in body. To solve this problem, Piper nigrum was introduced for its ability to strengthen bioavailability of other compounds.

PURPOSE

In most cases of TCM couplets, all ingredients were prepared and taken simultaneously, which in our opinion did not take full advantage of their interactions. Therefore, order of administration should be adjusted according to pharmacokinetic parameters of the ingredients, which the ones act as supplement can first be taken, and main therapeutic components followed when the former reached its peak.

METHOD

the extract of Piper nigrum (containing at least 95% piperine) was taken by rats 6h before taking Curcumae Longae Rhizoma extract (containing at least 95% curcumin). Then, a UPLC-MS-MS method was developed to determine their content in plasma simultaneously. Determination was carried out by on a C18 column within 5min by isocratic elution using 0.2% formic acid and acetonitrile (50:50, v/v). Tandem mass detection was conducted by selective reaction monitoring (SRM) via electrospray ionization (ESI) source in positive mode. Samples were pre-treated by liquid-liquid extraction (LLE), and verapamil was used as internal standard (IS).

RESULTS

For both curcumin and piperine, the proposed method had good linearity (r²=0.999) within the concentration range of 1-1000ng/ml, with good recovery, precision and stability. The lower limit of quantification (LLOQ) was 1ng/ml. As pharmacokinetic data indicated, Maximum concentration (C_max) of curcumin increased significantly to 394.06; the time reach maximum concentration (T_max) and elimination half-life (T_1/2) were 0.5 and 0.67h, respectively; CONCLUSION: The results provide a good strategy for the investigation of TCM formula especially the couplets, as well as a fast, selective and sensitive UPLC-MS-MS method determining active components in-vivo. Furthermore, the finding of "lagged stimulation" suggested that the use of complex formula should take pharmacokinetics into much more careful consideration.

Spice use in food: Properties and benefits

Spices are parts of plants that due to their properties are used as colorants, preservatives, or medicine. The uses of spices have been known since long time, and the interest in the potential of spices is remarkable due to the chemical compounds contained in spices, such as phenylpropanoids, terpenes, flavonoids, and anthocyanins. Spices, such as cumin (cuminaldehyde), clove (eugenol), and cinnamon (cinnamaldehyde) among others, are known and studied for their antimicrobial and antioxidant properties due to their main chemical compounds. These spices have the potential to be used as preservatives in many foods namely in processed meat to replace chemical preservatives. Main chemical compounds in spices also confer other properties providing a variety of applications to spices, such as insecticidal, medicines, colorants, and natural flavoring. Spices provide beneficial effects, such as antioxidant activity levels that are comparable to regular chemical antioxidants used so they can be used as a natural alternative to synthetic preservatives. In this review, the main characteristics of spices will be described as well as their chemical properties, different applications of these spices, and the advantages and disadvantages of their use.

In vitro assessment of the acaricidal activity of Piper longum, Piper nigrum, and Zingiber officinale extracts against Hyalomma anatolicum ticks

Ticks and tick-borne diseases are a major constraint for the sustainable cattle industry in the tropical and subtropical regions including the Indian subcontinent. The development of resistance to most of the commonly used acaricides leads to an attempt to screen plant extracts and their combinations for their possible acaricidal activity to develop an eco-friendly tick control alternative. An alcoholic and various aqueous extracts of Piper longum, Piper nigrum and Zingiber officinale and their combinations were evaluated for acaricidal activity against the three-host ixodid tick, Hyalomma anatolicum by larval immersion test using 14-21 days old unfed larvae. The efficacy was assessed by measuring larval mortality (%) and the lethal concentrations for 50% (LC50) and 95% (LC95) with their 95% confidence limits (CL) values were estimated by applying regression equation analysis to the probit transformed data of mortality. A concentration-dependent mortality response was recorded in all extracts prepared from seeds of P. longum and P. nigrum and their combinations. The highest acaricidal property was exhibited by the alcoholic extract of P. longum seeds with the minimum LC50 and LC95 (95% CL) values of 0.071% (0.07-0.072) and 0.135% (0.13-0.14), respectively, followed by alcoholic combinations. Interestingly, no acaricidal activity was recorded in extracts prepared from the rhizome of Z. officinale. The results indicated that the ethanolic extracts of P. longum and P. nigrum and their combinations can be used effectively for tick control in an integrated format.

Applications of response surface methodology and artificial neural network for decolorization of distillery spent wash by using activated Piper nigrum

Ethanol production from sugarcane molasses yields large volume of highly colored spent wash as effluent. This color is imparted by the recalcitrant melanoidin pigment produced due to the Maillard reaction. In the present work, decolourization of melanoidin was carried out using activated carbon prepared from pepper stem (Piper nigrum). The interaction effect between parameters were studied by response surface methodology using central composite design and maximum decolourization of 75 % was obtained at pH 7.5, Melanoidin concentration of 32.5 mg l-1 with 1.63 g 100ml-1 of adsorbent for 2hr 75min. Artificial neural networks was also used to optimize the process parameters, giving 74 % decolourization for the same parameters. The Langmuir and Freundich isotherms were applied for describing the biosorption equilibrium. The process was represented by the Langmuir isotherm with a correlation coefficient of 0.94. The first-order, second-order models were implemented for demonstrating the biosorption mechanism and, as a result, Pseudo second order model kinetics fitted best to the experimental data. The estimated enthalpy change (DH) and entropy change (DS) of adsorption were 32.195 kJ mol-1 and 115.44 J mol-1 K which indicates that the adsorption of melanoidin was an endothermic process. Continuous adsorption studies were conducted under optimized condition. The breakthrough curve analysis was determined using the experimental data obtained from continuous adsorption. Continuous column studies gave a breakthrough at 182 mins and 176 ml. It was concluded that column packed with Piper nigrum based activated carbon can be used to remove color from distillery spent wash.

Synthesis of coumaperine derivatives: Their NF-κB inhibitory effect, inhibition of cell migration and their cytotoxic activity

Coumaperine (an amide alkaloid, present in white piper) and its derivatives were synthesized and investigated for their cytotoxicity against L428 and A549 cells and their NF-κB inhibitory activity. It was found that the coumaperine derivatives CP-9 and CP-38 suppress NF-κB subunits p50 and p65 in nuclear fractions by western blot and by NF-κB luciferase reporter gene assay in a dose dependent manner. Confirmation of these results was obtained by confocal microscopy. CP-9, CP-32 and CP-38 also exhibited dose dependent cell cytotoxicity in a L428 cells expressing constitutively active NF-κB and in A549 cells, with an IC50 value of 43.25 μg/ml, 0.39 μg/ml and 16.85 μg/ml respectively against L428 cells and 57.15 μg/ml, 69.1 μg/ml and 63.2 μg/ml respectively against A549 cells. In addition, the coumaperine derivatives show remarkable inhibitory activity on the cancer cell migration assay against A549 lung adenocarcinoma cells at the concentrations of 5 μg/ml, 10 μg/ml, and 5 μg/ml of CP-9, CP-32 and CP-38 respectively. Aromatic substituents and number of olefinic double bond in coumaperine derivatives found to influence the inhibitory activity. In luciferase reporter gene assay, di-olefin conjugated coumaperine derivatives, CP-38, CP-32 and PIP exhibited higher inhibitory activity than their corresponding tri-olefin conjugated coumaperine derivatives, CP-102, CP-146 and PIP-155 respectively. CP-32 with a stronger electron donating group (-N(CH₃)₂) showed better inhibitory activity in luciferase reporter gene assay and in cell proliferation of L428 cells. Simple coumaperine derivative (CP-9, with no substituent) effectively inhibited A549 cells proliferation and migration than the other coumaperine derivatives. CP-9 and CP-38 diminish significantly the NF-κB subunits (p50 and p65) of L428 cells in nuclear fractions at the dosage of 10 μg/ml and 30 μg/ml respectively. Which clearly shows that CP-9 and CP-38 inactivate the NF-κB pathway in vitro.

Application of microwaves for microbial load reduction in black pepper (Piper nigrum L.)

BACKGROUND

Black pepper (Piper nigrum L.) is exposed to microbial contamination which could potentially create public health risk and also rejection of consignments in the export market due to non-adherance to microbial safety standards. The present study investigates the use of microwave (MW) radiation for microbial load reduction in black pepper and analyses the effect on quality.

RESULTS

Black pepper was exposed to MWs at two different power levels (663 and 800 W) at an intensity of 40 W g(-1) for different time intervals (1-15 min) and moisture content (110 and 260 g kg(-1) on a wet basis). The exposure of black pepper to MWs at 663 W for 12.5 min was found to be sufficient to reduce the microbial load to the permissible level suggested by the International Commission on Microbiological Specifications for Foods and the European Spice Association. The retention of volatile oil, piperine and resin was 91.3 ± 0.03, 87.6 ± 0.02 and 90.7 ± 0.05%, respectively, in MW-treated black pepper. The final moisture content after MW treatment was found to be 100 ± 1 g kg(-1) for black pepper containing initial moisture of 260 ± 3 g kg(-1) .

CONCLUSION

These results suggest that MW heating can be effectively used for microbial load reduction of black pepper without a significant loss in product quality. © 2016 Society of Chemical Industry.

Spices for Prevention and Treatment of Cancers

Spices have been widely used as food flavorings and folk medicines for thousands of years. Numerous studies have documented the antioxidant, anti-inflammatory and immunomodulatory effects of spices, which might be related to prevention and treatment of several cancers, including lung, liver, breast, stomach, colorectum, cervix, and prostate cancers. Several spices are potential sources for prevention and treatment of cancers, such as Curcuma longa (tumeric), Nigella sativa (black cumin), Zingiber officinale (ginger), Allium sativum (garlic), Crocus sativus (saffron), Piper nigrum (black pepper) and Capsicum annum (chili pepper), which contained several important bioactive compounds, such as curcumin, thymoquinone, piperine and capsaicin. The main mechanisms of action include inducing apoptosis, inhibiting proliferation, migration and invasion of tumors, and sensitizing tumors to radiotherapy and chemotherapy. This review summarized recent studies on some spices for prevention and treatment of cancers, and special attention was paid to bioactive components and mechanisms of action.

Determination of Multiresidue Pesticides in Botanical Dietary Supplements Using Gas Chromatography-Triple-Quadrupole Mass Spectrometry (GC-MS/MS)

A simplified sample preparation method in combination with gas chromatography-triple-quadrupole mass spectrometry (GC-MS/MS) analysis was developed and validated for the simultaneous determination of 227 pesticides in green tea, ginseng, gingko leaves, saw palmetto, spearmint, and black pepper samples. The botanical samples were hydrated with water and extracted with acetonitrile, magnesium sulfate, and sodium chloride. The acetonitrile extract was cleaned up using solid phase extraction with carbon-coated alumina/primary-secondary amine with or without C18. Recovery studies using matrix blanks fortified with pesticides at concentrations of 10, 25, 100, and 500 μg/kg resulted in average recoveries of 70-99% and relative standard deviation of 5-13% for all tested botanicals except for black pepper, for which lower recoveries of fortified pesticides were observed. Matrix-matched standard calibration curves revealed good linearity (r(2) > 0.99) across a wide concentration range (1-1000 μg/L). Nine commercially available tea and 23 ginseng samples were analyzed using this method. Results revealed 36 pesticides were detected in the 9 tea samples at concentrations of 2-3500 μg/kg and 61 pesticides were detected in the 23 ginseng samples at concentrations of 1-12500 μg/kg.

Piper nigrum ethanolic extract rich in piperamides causes ROS overproduction, oxidative damage in DNA leading to cell cycle arrest and apoptosis in cancer cells

ETHNOPHARMACOLOGICAL RELEVANCE

Ayurvedic and Chinese traditional medicine and tribal people use herbal preparations containing Piper nigrum fruits for the treatment of many health disorders like inflammation, fever, asthma and cancer. In Brazil, traditional maroon culture associates the spice Piper nigrum to health recovery and inflammation attenuation.

AIMS OF THE STUDY

The aim of the current work was to evaluate the relationship between reactive oxygen species (ROS) overproduction, DNA fragmentation, cell cycle arrest and apoptosis induced by Piper nigrum ethanolic extract and its antitumor activity.

METHODS

The plant was macerated in ethanol. Extract constitution was assessed by TLC, UV-vis and ESI-IT-MS/MS spectrometry. The cytotoxicity, proliferation and intracellular ROS generation was evaluated in MCF-7 cells. DNA damage effects were evaluated through intercalation into CT-DNA, plasmid DNA cleavage and oxidative damage in CT-DNA. Tumor growth inhibition, survival time increase, apoptosis, cell cycle arrest and oxidative stress were assessed in Ehrlich ascites carcinoma-bearing mice.

RESULTS

Extraction yielded 64mg/g (36% piperine and 4.2% piperyline). Treatments caused DNA damage and reduced cell viability (EC50=27.1±2.0 and 80.5±6.6µg/ml in MCF-7 and HT-29 cells, respectively), inhibiting cell proliferation by 57% and increased ROS generation in MCF-7 cells (65%). Ehrlich carcinoma was inhibited by the extract, which caused reduction of tumor growth (60%), elevated survival time (76%), cell cycle arrest and induced apoptosis. The treatment with extract increased Bax and p53 and inhibited Bcl-xL and cyclin A expression. It also induced an oxidative stress in vivo verified as enhanced lipid peroxidation and carbonyl proteins content and increased activities of glutathione reductase, superoxide dismutase and catalase. GSH concentration was decreased in tumor tissue from mice.

CONCLUSION

The ethanolic extract has cytotoxic and antiproliferative effect on MCF-7 cells and antitumor effect in vivo probably due to ROS overproduction that induced oxidative stress affecting key proteins involved in cell cycle arrest at G1/S and triggering apoptosis. Finally, the overall data from this study are well in line with the traditional claims for the antitumor effect of Piper nigrum fruits.

Occurrence of ochratoxin A in spices commercialized in Abidjan (Côte d'Ivoire)

Ochratoxin A (OTA) is a mycotoxin produced mostly by several species of Aspergillus and Penicillium. OTA is nephrotoxic in all animal species in which it has been tested and is cancerogenic in rodents. It is associated with Balkan endemic nephropathy. It is naturally present in many crop products such as cereals (barley, wheat, maize) and dried fruits, spices, coffee, wine, olives, and cocoa. The aim of this study was to assess the contamination of three Ivoirian spices with OTA (ginger, chili, and pepper) widely consumed by the population. A total of 90 spice samples (ginger: n = 30; chili: n = 30; pepper n = 30) was taken from various sales outlets of Abidjan. OTA was quantified using an HPLC apparatus coupled with a fluorimetric detector. The chili and ginger samples were contaminated with OTA at a mean concentration of 57.48 ± 174 and 0.12 ± 0.15 μg/kg, respectively. No contamination of the pepper samples was detected. Eight (26.67 %) of the chili samples exceeded the maximum limit of 15 μg/kg established by European regulation. These results should serve as an alert on the risk to the consumer population of these products that are highly contaminated with OTA.

Anti-cancer effects of Piper nigrum via inducing multiple molecular signaling in vivo and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Piper nigrum is widely used as a folk medicine including usage for pain relief, fevers, as well as an anti-cancer agent. However the crude extract of piperine free P. nigrum (PFPE), which inhibits breast cancer, and its mechanisms are still being kept secret. This research aims to elucidate the anti-cancer effects of PFPE and its mechanisms.

MATERIALS AND METHODS

Anti-cancer effects of PFPE were investigated in N-nitroso-N-methylurea (NMU)-induced mammary tumorigenesis rats and breast cancer cell lines MCF-7 and ZR-75-1. Furthermore, the cancer prevention effects of PFPE were investigated in rats. Western blotting was employed to study protein levels induced by PFPE.

RESULTS

PFPE was found to up-regulate p53, and down-regulate estrogen receptor (ER), E-cadherin (E-cad), matrix metalloproteinase 9 (MMP-9), matrix metalloproteinase 2 (MMP-2), c-Myc, and vascular endothelial growth factor (VEGF) levels in breast cancer rats. Moreover, PFPE decreased protein levels of E-cad, c-Myc, and VEGF in MCF-7 cells. These results suggest that PFPE can enhance breast cancer cell response to phytochemicals, then induce cell cycle arrest, and inhibit cancer cell proliferation resulting in tumor size decrease in the PFPE treated group. It further suggests that PFPE may suppress tumor cell invasion, migration, and angiogenesis. In addition, PFPE possessed cancer prevention effects through generation of reactive oxygen species (ROS) to higher cancer cell cellular stress.

CONCLUSIONS

PFPE may possess anti-cancer and cancer prevention effects; hence, it deserves further investigation as a novel candidate for breast cancer treatment.

Piperine from black pepper inhibits activation-induced proliferation and effector function of T lymphocytes

Piperine is a major alkaloid component of black pepper (Piper nigrum Linn), which is a widely consumed spice. Here, we investigated the effect of piperine on mouse T lymphocyte activation. Piperine inhibited polyclonal and antigen-specific T lymphocyte proliferation without affecting cell viability. Piperine also suppressed T lymphocyte entry into the S and G2 /M phases of the cell cycle, and decreased expression of G1 -associated cyclin D3, CDK4, and CDK6. In addition, piperine inhibited CD25 expression, synthesis of interferon-γ, interleukin (IL)-2, IL-4, and IL-17A, and the generation of cytotoxic effector cells. The inhibitory effect of piperine on T lymphocytes was associated with hypophosphorylation of Akt, extracellular signal-regulated kinase, and inhibitor of κBα, but not ZAP-70. The ability of piperine to inhibit several key signaling pathways involved in T lymphocyte activation and the acquisition of effector function suggests that piperine might be useful in the management of T lymphocyte-mediated autoimmune and chronic inflammatory disorders.

Effects of Extracts from Thai Piperaceae Plants against Infection with Toxoplasma gondii

Herbal medicines and natural herb extracts are widely used as alternative treatments for various parasitic diseases, and such extracts may also have potential to decrease the side effects of the standard regimen drugs used to treat toxoplasmosis (sulfadiazine-pyrimethamine combination). We evaluated how effective the Thai piperaceae plants Piper betle, P. nigrum and P. sarmentosum are against Toxoplasma gondii infection in vitro and in vivo. Individually, we extracted the piperaceae plants with ethanol, passed them through a rotary evaporator and then lyophilized them to obtain crude extracts for each one. The in vitro study indicated that the P. betle extract was the most effective extract at inhibiting parasite growth in HFF cells (IC₅₀ on RH-GFP: 23.2 μg/mL, IC₅₀ on PLK-GFP: 21.4 μg/mL). Furthermore, treatment of experimental mice with the P. betle extract for 7 days after infection with 1,000 tachyzoites of the T. gondii PLK strain increased their survival (survival rates: 100% in 400 mg/kg-treated, 83.3% in 100 mg/kg-treated, 33.3% in 25 mg/kg-treated, 33.3% in untreated mice). Furthermore, treatment with 400 mg/kg of the P. betle extract resulted in 100% mouse survival following infection with 100,000 tachyzoites. The present study shows that P. betle extract has the potential to act as a medical plant for the treatment of toxoplasmosis.

Assessment of metal contents in spices and herbs from Saudi Arabia

In the recent years, there has been a growing interest in monitoring heavy metal contamination of spices/herbs. Spices and herbs are sources of many bioactive compounds that can improve the tastes of food as well as influence digestion and metabolism processes. In the present study, the levels of some essential and toxic elements such as iron (Fe), zinc (Zn), copper (Cu), chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), lead (Pb), and cadmium (Cd), present in common spices/herbs that were purchased from the local market in Saudi Arabia, were analyzed by atomic absorption spectroscopy after digestion with nitric acid/hydrogen peroxide mixture. Samples from the following spices/herbs were used: turmeric, cloves, black pepper, red pepper, cumin, legume, cinnamon, abazir, white pepper, ginger, and coriander. The concentration ranges for the studied elements were found as 48.8-231, 4.7-19.4, 2.5-10.5, below detection level (BDL)-1.0, 8.8-490, 1.0-2.6, and BDL-3.7 µg g(-1) for Fe, Zn, Cu, Cr, Mn, Ni, and Pb, respectively, while Cd and Co levels were below the detection limit. Consumers of these spices/herbs would not be exposed to any risk associated with the daily intake of 10 g of spices per day as far as metals Fe, Zn, Cu, Cr, Mn, Ni, and Pb are concerned.

Increasing Carotenoid Bioaccessibility from Yellow Peppers Using Excipient Emulsions: Impact of Lipid Type and Thermal Processing

Many phytochemicals from fruits and vegetables exert biological activities that may be beneficial to human health, but these benefits are not fully realized because of their poor oral bioavailability. The objective of this research was to establish the potential of excipient emulsions to increase carotenoid bioaccessibility from raw and cooked yellow peppers using a gastrointestinal model that included oral, gastric, and intestine phases. The influence of oil type (medium chain triglycerides, MCT; long chain triglycerides, LCT; and, indigestible orange oil, OO) on microstructural changes, particle properties, lipid digestibility, and carotenoid bioaccessibility was investigated. Oil type had a major impact, with carotenoid bioaccessibility decreasing in the following order: LCT > MCT > OO > control (no oil). Conversely, thermal treatment (raw versus boiled) had little influence on carotenoid bioaccessibility. These results will facilitate the rational design of excipient emulsions that boost the bioavailability of phytochemicals in fruits and vegetables.

Piperine Congeners as Inhibitors of Vascular Smooth Muscle Cell Proliferation

Successful vascular healing after percutaneous coronary interventions is related to the inhibition of abnormal vascular smooth muscle cell proliferation and efficient re-endothelialization. In the search for vascular smooth muscle cell anti-proliferative agents from natural sources we identified piperine (1), the main pungent constituent of the fruits from Piper nigrum (black pepper). Piperine inhibited vascular smooth muscle cell proliferation with an IC50 of 21.6 µM, as quantified by a resazurin conversion assay. Investigations of ten piperamides isolated from black pepper fruits and 15 synthesized piperine derivatives resulted in the identification of three potent vascular smooth muscle cell proliferation inhibitors: the natural alkaloid pipertipine (4), and the two synthetic derivatives (2E,4E)-N,N-dibutyl-5-(3,5-dimethoxyphenyl)penta-2,4-dienamide (14) and (E)-N,N-dibutyl-3-(naphtho[2,3-d][1,3]dioxol-5-yl)acrylamide (20). They showed IC50 values of 3.38, 6.00, and 7.85 µM, respectively. Furthermore, the synthetic compound (2E,4E)-5-(4-fluorophenyl)-1-(piperidin-1-yl)penta-2,4-dien-1-one (12) was found to be cell type selective, by inhibiting vascular smooth muscle cell proliferation with an IC50 of 11.8 µM without influencing the growth of human endothelial cells.

Derivatives form better lipoxygenase inhibitors than piperine: in vitro and in silico study

Piperine is a secondary metabolite of black pepper. Its uses in medicine were already studied. However, its derivatives have not gained considerable attention. In the presented study, the Lipoxygenase (LOX) inhibitory activity of piperine and its derivatives, piperonylic acid, piperic acid, and piperonal have been assessed and compared by enzyme kinetics, ITC and molecular modeling experiments. The presented investigations expressed that all the studied compounds inhibited LOX by binding at its active site. The IC(50) values of these compounds were deduced from the kinetics data and found to be 85.79, 43.065, 45.17, and 50.78 μm for piperine, piperonylic acid, piperic acid, and piperonal, respectively. The binding free energies obtained from ITC experiments were -7.47, -8.33, -8.09, and -7.86 kcal/mol for piperine, piperonylic acid, piperic acid, and piperonal, respectively. Similarly, the glide scores obtained for piperine, piperonylic acid, piperic acid, and piperonal were -7.28, -10.32, -10.72, and -9.57 kcal/mol, respectively. The results of ITC and molecular modeling experiments suggested that piperonylic acid and piperonal exhibit stronger binding at the active site than piperine does. From the presented studies, it could be concluded that derivatives of piperine may be of higher significance than piperine for certain medicinal applications, implicating (Ayurvedic) fermented herbal drugs with piperine in them.

Effects of Piper nigrum extracts: Restorative perspectives of high-fat diet-induced changes on lipid profile, body composition, and hormones in Sprague-Dawley rats

CONTEXT

Piper nigrum Linn (Piperaceae) (PnL) is used in traditional medicine to treat gastric ailments, dyslipidemia, diabetes, and hypertension.

OBJECTIVE

The present study explores the possible protective effects of P. nigrum extracts on high-fat diet-induced obesity in rats.

MATERIALS AND METHODS

High-fat diet-induced obese rats were treated orally with 200 mg/kg bw of different extracts (hexane, ethylacetate, ethanol, and aqueous extracts) of PnL for 42 d. The effects of PnL extracts on body composition, insulin resistance, biochemical parameters, leptin, adiponectin, lipid profile, liver marker enzymes, and antioxidants were studied.

RESULTS AND DISCUSSION

The HFD control group rats showed a substantial raise in body weight (472.8 ± 9.3 g), fat% (20.8 ± 0.6%), and fat-free mass (165.9 ± 2.4 g) when compared with normal control rats whose body weight, fat%, and fat-free mass were 314.3 ± 4.4 g, 6.4 ± 1.4%, and 133.8 ± 2.2 g, respectively. Oral administration of ethyl acetate or aqueous extracts of PnL markedly reduced the body weight, fat%, and fat-free mass of HFD-fed rats. In contrast to the normal control group, a profound increase in plasma glucose, insulin resistance, lipid profile, leptin, thiobarbituric acid reactive substance (TBARS), and the activities of lipase and liver marker enzymes, and a decrease in adiponectin and antioxidant enzymes were noted in HFD control rats. Administration of PnL extracts to HFD-induced obese rats significantly (p < 0.05) restored the above profiles.

CONCLUSION

PnL extracts significantly reduced the body weight, fat%, and ameliorated HFD-induced hyperlipidemia and its constituents.

Development of piperic acid derivatives from Piper nigrum as UV protection agents

CONTEXT

There is a need for the discovery of novel natural and semi-synthetic sunscreen that is safe and effective. Piperine has a UV absorption band of 230-400 nm with high molar absorptivity. This compound has a high potential to be developed to sunscreen.

OBJECTIVE

This study develops new UV protection compounds from piperine by using chemical synthesis.

MATERIALS AND METHODS

Piperine was isolated from Piper nigrum L. (Piperaceae) fruits, converted to piperic acid by alkaline hydrolysis, and prepared as ester derivatives by chemical synthesis. The piperate derivatives were prepared as 5% o/w emulsion, and the SPF values were evaluated. The best compound was submitted to cytotoxicity test using MTT assay.

RESULTS

Piperic acid was prepared in 86.96% yield. Next, piperic acid was reacted with alcohols using Steglich reaction to obtain methyl piperate, ethyl piperate, propyl piperate, isopropyl piperate, and isobutyl piperate in 62.39-92.79% yield. All compounds were prepared as 5% oil in water emulsion and measured its SPF and UVA/UVB values using an SPF-290S analyzer. The SPF values (n = 6) of the piperate derivatives were 2.68 ± 0.17, 8.89 ± 0.46, 6.86 ± 0.91, 16.37 ± 1.8, and 9.68 ± 1.71. The UVA/UVB ratios of all compounds ranged from 0.860 to 0.967. Cytotoxicity of isopropyl piperate was evaluated using human skin fibroblast cells and the IC50 was equal to 120.2 μM.

DISCUSSION AND CONCLUSION

From the results, isopropyl piperate is an outstanding compound that can be developed into a UV protection agent.

Piperine inhibits proliferation of human osteosarcoma cells via G2/M phase arrest and metastasis by suppressing MMP-2/-9 expression

The piperidine alkaloid piperine, a major ingredient in black pepper, inhibits the growth and metastasis of cancer cells both in vivo and in vitro, although its mechanism of action is unclear. Furthermore, its anticancer activity against osteosarcoma cells has not been reported. In this study, we show that piperine inhibited the growth of HOS and U2OS cells in dose- and time-dependent manners but had a weaker effect on the growth of normal hFOB cells. Piperine inhibited osteosarcoma cell proliferation by causing G2/M phase cell cycle arrest associated with decreased expression of cyclin B1 and increased phosphorylation of Cyclin-dependent kinase-1(CDK1) and checkpoint kinase 2 (Chk2). In addition, piperine treatment inhibited phosphorylation of Akt and activated phosphorylation of c-Jun N-terminal kinase (c-JNK) and p38 mitogen-activated protein kinase (MAPK) in HOS and U2OS cells. Piperine induced colony formation in these two cell types. We proved that piperine could suppress the metastasis of osteosarcoma cells using scratch migration assays and Transwell chamber tests. Moreover, gelatin zymography showed that piperine inhibited the activity of matrix metalloproteinase (MMP)-2/-9 and increased the expression of tissue inhibitor of metalloproteinase (TIMP)-1/-2. Taken together, our results indicate that piperine inhibits proliferation, by inducing G2/M cell cycle arrest, and the migration and invasion of HOS and U2OS cells, via increased expression of TIMP-1/-2 and down-regulation of MMP-2/-9. These findings support further study of piperine as a promising therapeutic agent in the treatment of osteosarcoma.

Production of the pepper aroma compound, (-)-rotundone, by aerial oxidation of α-guaiene

The aroma link between pepper and wine has recently been elucidated to be due to the important aroma compound rotundone. To date, rotundone is the only known impact odorant with a peppery aroma. Although the concentration found in products of natural origin is small, the odor detection threshold is among the lowest of any natural product yet discovered. We report herein the identification of the first known precursor to rotundone, namely, α-guaiene, and that one mechanism of transformation is simple aerial oxidation.

Antifungal activity and computational study of constituents from Piper divaricatum essential oil against Fusarium infection in black pepper

Fusarium disease causes considerable losses in the cultivation of Pipernigrum, the black pepper used in the culinary world. Brazil was the largest producer of black pepper, but in recent years has lost this hegemony, with a significant reduction in its production, due to the ravages produced by the Fusarium solani f. sp. piperis, the fungus which causes this disease. Scientific research seeks new alternatives for the control and the existence of other Piper species in the Brazilian Amazon, resistant to disease, are being considered in this context. The main constituents of the oil of Piper divaricatum are methyleugenol (75.0%) and eugenol (10.0%). The oil and these two main constituents were tested individually at concentrations of 0.25 to 2.5 mg/mL against F. solani f. sp. piperis, exhibiting strong antifungal index, from 18.0% to 100.0%. The 3D structure of the β-glucosidase from Fusarium solani f. sp. piperis, obtained by homology modeling, was used for molecular docking and molecular electrostatic potential calculations in order to determine the binding energy of the natural substrates glucose, methyleugenol and eugenol. The results showed that β-glucosidase (Asp45, Arg113, Lys146, Tyr193, Asp225, Trp226 and Leu99) residues play an important role in the interactions that occur between the protein-substrate and the engenol and methyleugenol inhibitors, justifying the antifungal action of these two phenylpropenes against Fusarium solani f. sp. piperis.

Locations of radical species in black pepper seeds investigated by CW EPR and 9GHz EPR imaging

In this study, noninvasive 9GHz electron paramagnetic resonance (EPR)-imaging and continuous wave (CW) EPR were used to investigate the locations of paramagnetic species in black pepper seeds without further irradiation. First, lithium phthalocyanine (LiPC) phantom was used to examine 9GHz EPR imaging capabilities. The 9GHz EPR-imager easily resolved the LiPC samples at a distance of ∼2mm. Then, commercially available black pepper seeds were measured. We observed signatures from three different radical species, which were assigned to stable organic radicals, Fe(3+), and Mn(2+) complexes. In addition, no EPR spectral change in the seed was observed after it was submerged in distilled H2O for 1h. The EPR and spectral-spatial EPR imaging results suggested that the three paramagnetic species were mostly located at the seed surface. Fewer radicals were found inside the seed. We demonstrated that the CW EPR and 9GHz EPR imaging were useful for the determination of the spatial distribution of paramagnetic species in various seeds.

Screening of β-secretase and acetylcholinesterase inhibitors from plant resources

The therapeutic agents for dementia are limited due to the complex system underlying the mechanisms. Taking a preventive point of view, we focused on the inhibition of β-secretase and acetylcholinesterase (AChE). In addition, plant resources including herbs and spices have been widely consumed, and further, may be consumed for a long period over a lifetime. Considering this background, we screened β-secretase and AChE inhibitors from curry spices. Amongst them, curry leaf, black pepper, and turmeric extracts were effective to inhibit β-secretase. Furthermore, black pepper and turmeric extracts were also effective to inhibit AChE. Having these results in hand, we focused on the investigation of β-secretase inhibitors since the inhibitor of this enzyme has not previously been well investigated. As a result, α- and β-caryophyllene, β-caryophyllene oxide (from curry leaf), piperine (from black pepper), curcumin, demethoxycurcumin, and bisdemethoxycurcumin (from turmeric) were successfully identified as low molecular inhibitors. This is the first report to determine α- and β-caryophyllene, β-caryophyllene oxide, and piperine as β-secretase inhibitors. These compounds may pass through the blood brain barrier since their molecular weights are relatively low.

Evaluation of in vitro aldose reductase inhibitory potential of alkaloidal fractions of Piper nigrum, Murraya koenigii, Argemone mexicana, and Nelumbo nucifera

BACKGROUND

Aldose reductase is primarily involved in development of long-term diabetic complications due to increased polyol pathway activity. The synthetic aldose reductase inhibitors are not very successful clinically. Therefore, the natural sources may be exploited for safer and effective aldose reductase inhibitors.

METHODS

In the present study, the aldose reductase inhibitory potential of hydroalcoholic and alkaloidal extracts of Piper nigrum, Murraya koenigii, Argemone mexicana, and Nelumbo nucifera was evaluated. The hydroalcoholic and alkaloidal extracts of the selected plants were prepared. The different concentrations of hydroalcoholic and alkaloidal extracts of these plants were evaluated for their goat lens aldose reductase inhibitory activity using dl-glyceraldehyde as substrate. The aldose reductase inhibitory potential of extracts was assessed in terms of their IC50 value.

RESULTS

Amongst the hydroalcoholic extracts, the highest aldose reductase inhibitory activity was shown by P. nigrum (IC50 value 35.64±2.7 μg/mL) followed by M. koenigii (IC50 value 45.67±2.57 μg/mL), A. mexicana (IC50 value 56.66±1.30 μg/mL), and N. nucifera (IC50 value 59.78±1.32 μg/mL). Among the alkaloidal extracts, highest inhibitory activity was shown by A. mexicana (IC50 value 25.67±1.25 μg/mL), followed by N. nucifera (IC50 value 28.82±1.85 μg/mL), P. nigrum (IC50 value 30.21±1.63 μg/mL), and M. koenigii (IC50 value 35.66±1.64 μg/mL).

CONCLUSIONS

It may be concluded that the alkaloidal extracts of these plants possess potent aldose reductase inhibitory activity and may be therapeutically exploited in diabetes-related complications associated with increased activity of aldose reductase.